This invention relates to laying down of large sheets of film, especially for temporary protective purposes.
It is known that it is sometimes desirable to provide a protective cover over plants to prevent damage from frost and the like. This is relatively easy to do with small gardens, but is quite difficult with large fields of crops.
Furthermore, it is also known to be desirable to provide a protective cover for athletic playing fields such as football fields and baseball diamonds, to protect the grass cover from heavy rain and the like.
It is desirable that a field cover be as light in weight as possible in view of its large size. Polyethylene and similar plastic films arequite adequate for the job, but are subject to the disadvantage of being available in rolls of limited length, such as about 10 feet. To manufacture a one piece longer roll for a field of 100-500 ft. width, and then to transport the roll to the field, is an almost impossible task because the roll is so unwieldy.
The present invention is directed to a solution of the aforementioned problem and involves the concept of "manufacturing" a long roll of plastic film from short rolls in situ, while simultaneously laying the film onto the field.
In accordance with the invention, a plurality of short plastic film rolls are supported on drivable rollers, which in turn are mounted on a plurality of spaced trucks extending along the width of the field. The axes of the film rolls are parallel, but alternate rolls are staggered with every other roll being disposed either forwardly or rearwardly of the adjacent rolls. The roll ends overlap and, as the trucks move longitudinally down the field to lay down the film, the overlapping edges of the film are sealingly joined together as they leave their respective rolls and just before being laid down.